Confined Space Entry Permit Requirements: What OSHA 1910.146 Says

Under 29 CFR 1910.146(e)(1), "before entry is authorized, the employer shall document the completion of measures required by paragraph (d)(3) of this section by preparing an entry permit." The permit is not paperwork added on top of the entry. It is the record that the isolation, testing and rescue arrangements the program calls for are in place, signed by the person accountable for them and posted where the people going in can read it. This article covers which spaces need a permit, who signs it, the 15 items it must identify, and what happens to it when the job is done.

A note on scope: this summarizes the federal OSHA general industry standard. Construction, shipyards and agriculture have their own rules, states with OSHA-approved plans can set different requirements, and nothing here is legal advice.

Which spaces need a permit

The standard works in two steps. A confined space, under 1910.146(b), is one that is large enough for an employee to bodily enter and work in, has limited or restricted means for entry or exit, and is not designed for continuous occupancy. Tanks, vessels, silos, hoppers, vaults and pits are the standard's examples.

A permit-required confined space, or permit space, is a confined space with one or more of four characteristics: it contains or could contain a hazardous atmosphere; it contains a material that could engulf an entrant; it has an internal configuration that could trap or asphyxiate an entrant, such as inwardly converging walls or a floor that slopes down to a smaller cross-section; or it contains any other recognized serious safety or health hazard.

The definition of a hazardous atmosphere sets the numbers that come up later on the permit: a flammable gas, vapor or mist above 10 percent of its lower flammable limit; combustible dust at or above its lower flammable limit; oxygen below 19.5 percent or above 23.5 percent; any substance above a permissible exposure limit or dose published in subparts G or Z; or any other condition that is immediately dangerous to life or health.

Under (c)(1), the employer evaluates the workplace to determine whether any spaces are permit spaces. Under (c)(2), exposed employees are informed of their existence, location and danger by danger signs or another equally effective means; the standard says a sign reading "DANGER—PERMIT-REQUIRED CONFINED SPACE, DO NOT ENTER" would satisfy it. Under (c)(4), an employer whose employees will enter permit spaces develops a written permit space program, available for inspection by employees. An employer that decides its employees will not enter must, under (c)(3), take effective measures to prevent them from entering.

Two narrower paths exist: the (c)(5) alternate procedures, where continuous forced air ventilation alone controls a purely atmospheric hazard, and (c)(7) reclassification of a space whose hazards have all been eliminated. Both rest on a written certification with the date, the location of the space and a signature. Everything else is a permit entry.

The permit system: who signs, where it is posted, how long it lasts

Paragraph (e) sets the life of a permit in six steps.

1. It is prepared before entry is authorized and documents that the (d)(3) measures are complete: acceptable entry conditions specified, the space isolated and purged, inerted, flushed or ventilated as needed, and a way to verify that conditions stay acceptable throughout the entry. (e)(1)

1. The entry supervisor signs it before entry begins. Under (e)(2), "the entry supervisor identified on the permit shall sign the entry permit to authorize entry."

1. It is available to the entrants at the time of entry, by posting at the entry portal or another equally effective means, "so that the entrants can confirm that pre-entry preparations have been completed." (e)(3)

1. It lasts no longer than the job. Under (e)(4), the duration of the permit may not exceed the time required to complete the task identified on it.

1. The entry supervisor cancels it when the entry operations are complete, or when "a condition that is not allowed under the entry permit arises in or near the permit space." (e)(5)

1. Cancelled permits are kept for at least one year, with any problems encountered during the entry noted on them "so that appropriate revisions to the permit space program can be made." (e)(6) Those permits feed the program review required by (d)(14) within one year after each entry.

What the permit must identify

Paragraph (f) lists the 15 things an entry permit "shall identify." Any format works, including the sample permits in the standard's non-mandatory appendix D, as long as the entries are there. The confined space entry permit template follows this list item for item.

1. The permit space to be entered.

1. The purpose of the entry.

1. The date and the authorized duration of the permit.

1. The authorized entrants, by name or by another means, such as a roster or tracking system, that lets the attendant determine quickly and accurately who is inside.

1. The attendants, by name.

1. The entry supervisor, by name, with a space for the signature or initials of the supervisor who originally authorized entry.

1. The hazards of the space.

1. The measures used to isolate the space and to eliminate or control its hazards before entry: lockout or tagging of equipment, purging, inerting, ventilating and flushing.

1. The acceptable entry conditions.

1. The results of initial and periodic tests, with the names or initials of the testers and an indication of when each test was performed.

1. The rescue and emergency services that can be summoned, and the means for summoning them, such as the equipment to use and the numbers to call.

1. The communication procedures entrants and attendants use to stay in contact.

1. The equipment to be provided: PPE, testing, communications, alarm and rescue equipment.

1. Any other information necessary for employee safety in the particular space.

1. Any additional permits issued for work in the space, such as a hot work permit. How that one works is covered in hot work permit requirements.

The testing behind item 10

Under (d)(5), conditions in the space are tested "to determine if acceptable entry conditions exist before entry is authorized to begin," then tested or monitored as necessary to confirm they are being maintained during the entry. The order is fixed by (d)(5)(iii): "test first for oxygen, then for combustible gases and vapors, and then for toxic gases and vapors." The non-mandatory appendix B explains why: most combustible gas meters will not read reliably without enough oxygen, and fire is usually the more immediate threat.

Each authorized entrant, or their representative, may observe the pre-entry and any later testing, may ask for a reevaluation of the space, and is given the results immediately, under (d)(5)(iv) through (vi). The instrument itself has to be ready for this; see gas detector bump test requirements.

The people the permit names

Under (d)(6), at least one attendant is outside the permit space for the duration of the entry. The attendant's duties under (i) are built around the names on the permit: continuously maintain an accurate count of entrants, order an evacuation on detecting a prohibited condition or a situation that could endanger the entrants, summon rescue as soon as entrants may need help to escape, and perform "no duties that might interfere with the attendant's primary duty to monitor and protect the authorized entrants."

The entry supervisor, under (j)(2), verifies "by checking that the appropriate entries have been made on the permit" that every test the permit specifies has been done and every procedure and piece of equipment is in place before endorsing it, verifies that rescue services are available and the means for summoning them are operable, removes unauthorized individuals, and terminates the entry and cancels the permit. One person may serve as entry supervisor and attendant or entrant if trained and equipped for each role.

Rescue arrangements under (k) stand behind item 11. An employer that designates a rescue service evaluates its ability to respond in a timely manner for the hazards identified; employees designated as rescuers practice permit space rescues at least once every 12 months. Under (k)(3), a retrieval system is used whenever an entrant enters, unless it would increase the overall risk or would not contribute to the rescue, with a mechanical device available to retrieve people from vertical spaces more than 5 feet deep.

Making it real

A permit on a clipboard at the portal can meet (e)(3), and the same sheet in a filing cabinet can meet (e)(6). What it does not do well is show, a year later, that the readings came before the signature, or carry its noted problems into the program review.

• Scan the space, not the form. A QR code or NFC tag at the portal, scanned as the permit is opened, ties the permit to that space and its history: previous permits, their noted problems and the hazards for item 7.
• Make the permit the form. The 15 items as fields on a phone, with each test reading entered against the acceptable entry condition and a name and time on every test, give the entry supervisor exactly what (j)(2) asks them to check before signing.
• Make cancellation an outcome. When the permit is cancelled for a prohibited condition, the condition becomes a finding with an owner, and the note (e)(6) requires is written while it is fresh. Why findings stall between the form and the fix is covered in why inspection findings stall before they become work orders.

How to design permit forms so the sign-off sequence cannot be skipped is covered in digital permit to work and lockout/tagout design, and the same approach applies to the rest of a site's safety checks: safety inspections that get done.

Quick summary

• 1910.146(e): prepare the permit before entry; the entry supervisor signs it before entry begins; post it at the portal; it lasts no longer than the job; cancel it when the work is done or a prohibited condition arises; keep cancelled permits at least one year with any problems noted.
• 1910.146(f): the permit identifies 15 items, from the space and purpose through the people, hazards, isolation, acceptable entry conditions and test results, to rescue, communications, equipment and any other permits such as hot work.
• 1910.146(d)(5): test oxygen first, then combustibles, then toxics, before entry and as needed during it.
• 1910.146(k)(3): a retrieval system on every entrant unless it adds risk, with a mechanical device for vertical spaces more than 5 feet deep.

If your sites issue entry permits alongside hot work permits and isolation checks, see how Vardian handles safety inspections and corrective action: a scan at the portal, the 15 items captured as a form with readings checked against limits, and a cancelled permit that becomes a finding with an owner.